Internal combustion engine



Sept. 29, 1931. R. w. HARROUN INTERNAL COMBUSTION ENGINE Filed Sept. 3. 1929 INVENTOR 37 71472479 0517? ATTO RN EY/ Patented Sept. 29, 1931 UNITED STATES PATENT OFFICE RAY W. HARROUN, OF DETROIT, MICHIGAN INTERNAL COMBUSTION ENGINE Application filed September 3, 1929. Serial No. 390,167.

In the present state of the art with L-head internal combustion engines it is usual to arrange adjacent inlet and exhaust valves of m substantially equal area in the L and at one side of the cylinder. In order to provide free passage for the gases the valve chamber must be made of suflicient depth not only to permit of proper valve lift but also -to provide clearance over the valves for the flow of gases. Furthermore, as the gases enter and leave their respective ports on all sides of the circumfe'renceof .the valve the portion of the gases on the outer side must BIS-make a quick bend to return over the valve in the direction ofthe bylinden- Thus with such construct-ions the free flow of the gases is impeded while the necessary clearance above the valves increases the volume of the compression chamber so as to reduce the height of the compression. Another difficulty encountered is the increased tendency to a detonation incident to higher compressions, particularly where the piston and ex- -haust valve are of relatively large diameter. With my improved construction I have avoided the difiiculties as above outlined, first by substituting for a single cylinder and its compression chamber a pair ofcylinders -of smaller diameters but of combined equal area and a single compression chamber com-H municating with both cylinders: second, by aconstruction and arrangement of valves such that thegases are free to pass between the cylinders and the valve ports without any sharp change in direction or the necessity o the intake gases passing over the top of the inlet valve: third, by the use of a single inlet -valve for both cylinders, said valve being arranged centrally within the combustion chamber intermediate said cylinders; fourth, by the use of a pair of exhaust valves on opposite sides of'the inlet valve and so located as to be bathed by the flow of inlet gases to the cylinder, thereby facilitating the dissi- 1 pation of heat. This arrangement permits of considerably reducing the volume of the compression chamber while still providing the requisite clearance for valve lift. My invention therefore consists in this improved construction and further in various specific features as hereinafter set forth.

In the drawings: Figure 1 is a horizontal section through the combustion chamber of an internal com- 05 bustion engine of my improved construction;

Figure 2 is a vertical cross section on line 22 of Figure 1;

, Figure 3 is a plan view of a multi-cylinder block embodying my improvement.

As illustrated, A and A are two adj acent'engine cylinders which have a combined volume equal to that of the single cylinder for which they are substituted. B is a combustion chamber formed in an L-head on one side of the pair of cylinders A. A. Within this combustion chamber are arranged a single inlet port C controlled by the poppet valve D and a-pair of exhaust ports E. E, controlled by poppet valves F and F. The port C is arranged centrally between the cylinders A and A so as to overlap the same, thereby shifting its axis nearer to the plane of the axes of said cylinders. The exhaust ports E and E are arranged on opposite sides of the port C and preferably directly opposite their respective cylinders. but as these ports are of smaller diameter than the port C they require no further extension of the L- head. The port C which is of an area sufficient for the combined areas of the cylinders A A is so arranged that the gases passing from said port half way around its perimeter are free to flow in the general direction of, one

f of the cylinders and without any sharp bend.

while the gases passing out on the opposite side of the perimeter flow in the general direction of the other cylinder. This dispenses with the necessity for any clearance above the port C greater than required for the lift of the valve. On the otherhand the exhaust valves lie in the path of the flow of the intake gases and are more rapidly cooled thereby.

In operation the two-cylinders A A act as a unit, both simultaneously receiving the combustible charge upon the lifting of the valve D and simultaneously exhausting the products of combustion upon the lifting of the valves F and F. By reason of the more compact arran ement of the valve ports the area of the com ustion chamber in horizontal cross section need be no greater than would be required with a' single cylinder of equal volume and having one inlet and one exhaust valve and inlet and exhaust valves. Also due to the fact that only mechanical clearance 'is required above the valves and further due to the increased perimeter of the two exhaust valves, the depth of the explosion chamber may be reduced. This results either in higher compression without impedance to thefiow of gases between the cylinders and ports or the same compression with larger port areas. A further advantage is that the cross sectional area of the connection between the cylinder and the combustion chamber is restricted which increases the turbulence in the combustible gases.

What I claim as my invention is:

1. An internal combustion engine comprisng a pair of adjacent cylinders with. parallel axes, a common combustion chamber-having a restricted area connecting the same with said cylinders and provided with a single valve controlled inlet port arranged between and overlapping said cylinders and a pair of exhaust ports of smaller diameter arranged on opposite sides of said inlet port.

2. An internal combustion engine comprising a pair of cylinders, a common laterally off-set combustion chamber connected with said cylinders and provided with a single in let port arranged centrally between and overlapping said cylinders, and a pair of exhaust ports laterally opposite the respective cylinders, the depth of said combustion chamber being restricted to provide merely mechanical clearance for movement of the valves, and poppet valves for said inlet and exhaust ports.

3. In an internal combustion engine of the L-head type, a pair of cylinders having parallel axes, a common combustionchamber for said cylinders provided with a single valve controlled inlet port, arranged between and overlapping said cylinders and a pair of exhaust ports of smaller diameter arranged on opposite sides of said inlet port.

4. In an internal combustion engine of the L-head type, a pair of closely arranged cylinders having parallel axes, a common laterally ofi'set combustion chamber connected with said cylinders, provided with a single relatively large inlet port arranged centrally RAY W. HARROUN. 

